Ribosome biogenesis adaptation in resistance training-induced human skeletal muscle hypertrophy
Abstract
Resistance training (RT) has the capacity to increase skeletal muscle mass, which is due in part to transient increases in the rate of muscle protein synthesis during postexercise recovery. The role of ribosome biogenesis in supporting the increased muscle protein synthetic demands is not known. This study examined the effect of both a single acute bout of resistance exercise (RE) and a chronic RT program on the muscle ribosome biogenesis response. Fourteen healthy young men performed a single bout of RE both before and after 8 wk of chronic RT. Muscle cross-sectional area was increased by 6 ± 4.5% in response to 8 wk of RT. Acute RE-induced activation of the ERK and mTOR pathways were similar before and after RT, as assessed by phosphorylation of ERK, MNK1, p70S6K, and S6 ribosomal protein 1 h post exercise. Phosphorylation of TIF-IA was also similarly elevated following both RE sessions. Cyclin D1 protein levels, which appeared to be regulated at the translational rather than transcriptional level, were acutely increased after RE. UBF was the only protein found to be highly phosphorylated at rest after 8 wk of training. Also, muscle levels of the rRNAs, including the precursor 45S and the mature transcripts (28S, 18S, and 5.8S), were increased in response to RT. We propose that ribosome biogenesis is an important yet overlooked event in RE-induced muscle hypertrophy that warrants further investigation.
Keywords
Cyclin D1, Ribosomal RNA, Transcription initiation factor 1A, Upstream binding protein, binding protein, cyclin D1, mammalian target of rapamycin, messenger RNA, mitogen activated protein kinase 1, mitogen activated protein kinase 3, mitogen activated protein kinase interacting kinase 1, polymerase RNA I polypeptide B, ribosome protein, ribosome RNA, RNA polymerase, S6 kinase, S6 ribosomal protein 1, transcription factor, transcription initiation factor 1a, unclassified drug, upstream binding protein, adaptation, adult, Article, biogenesis, body composition, computer assisted tomography, controlled study, dual energy X ray absorptiometry, enzyme phosphorylation, human, human experiment, human tissue, male, muscle hypertrophy, muscle level, normal human, priority journal, quadriceps femoris muscle, real time polymerase chain reaction, resistance training, ribosome, ribosome subunit, translation initiation, adaptation, adolescent, energy metabolism, hypertrophy, metabolism, pathology, physiology, randomized controlled trial, rest, ribosome, RNA translation, skeletal muscle, young adult, Adaptation, Physiological, Adolescent, Adult, Energy Metabolism, Humans, Hypertrophy, Male, Metabolic Networks and Pathways, Muscle, Skeletal, Peptide Chain Initiation, Translational, Resistance Training, Rest, Ribosomes, Young Adult
Document Type
Journal Article
Date of Publication
2015
Publisher
American Physiological Society
School
Centre for Exercise and Sports Science Research / School of Exercise and Health Sciences
RAS ID
21553
Copyright
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Comments
Figueiredo, V.C., Caldow, M.K., Massie, V., Markworth, J.F., Cameron-Smith, D., Blazevich, A.J. (2015). Ribosome biogenesis adaptation in resistance training-induced human skeletal muscle hypertrophy. In American Journal of Physiology - Endocrinology and Metabolism, 309(1), E72-E83. Available here.